A student wearing a face mask prays before the start of the annual college entrance examination amid the coronavirus pandemic at an exam hall in Seoul, South Korea, Thursday, December 3, 2020. South Korean officials are urging people to remain at home if possible and cancel gatherings as about half a million students prepare for a crucial national college exam. (Photo by Kim Hong-Ji/Pool Photo via AP Photo)

Alejandro Ccasa prays after waiting three days next to an empty oxygen tank for his uncle who has COVID-19 outside a refill shop where he is the first in line before it opens in Callao, Peru, early Tuesday, February 2, 2021. Ccasa said his family has one large tank and it gives about four hours of oxygen therapy. (Photo by Martin Mejia/AP Photo)

A volunteer operates a remote controlled disinfection robot to disinfect a residental area amid the COVID-19 coronavirus outbreak in Wuhan in China's central Hubei province on March 16, 2020. China tightened quarantine measures for international arrivals on March 16 as the country worries about a rise in imported cases of the deadly coronavirus and anger rages online at how Europe and the United States are handling the pandemic. (Photo by AFP Photo/China Stringer Network)

An orphan plays with her new hula hoop during the food and toy distribution, for total about 500 orphans in 11 orphanages, by National Muslim COVID-19 Response Committee to celebrate Eid al-Fitr, the Muslim holiday which marks the end of the fasting month of Ramadan at Good hope markazil Banatil Islamia orphans centre in Nairobi, Kenya, on May 25, 2020. (Photo by Yasuyoshi Chiba/AFP Photo)

Little owl chicks in Northumberland, UK on August 19, 2018. Strutting up and down and barrelling through the air, these Little Owl chicks will soon be fending for themselves. The intense little birds were snapped by wildlife photographer Bill Doherty in his native Northumberland. The chicks have about seven or eight weeks to learn their survival skills before their parents drive them away to fend for themselves. (Photo by Bill Doherty/South West News Service)

In this November 17, 2014 photo, Pancho, a domesticated huitia, confronts a camera, in Bainoa, Cuba. With their rope-like, dark tails, long front teeth, and whiskers that appear to be vibrating, huitias look like giant rats. They measure nearly a foot long (about 30 centimeters), with the largest ones weighing in bigger than a small dog. (Photo by Ramon Espinosa/AP Photo)

A participant in the traditional dance of Los Historiantes poses for a picture prior to performing in the festivity held in the honour of Saint James, in Santiago Nonualco July 22, 2015. The traditional dance was brought to Latin America by the Spanish, and participants each dramatise an episode of the battles between the Christians and the Moors that took place on the Iberian Peninsula about eight centuries ago, according to the dancers. (Photo by Jose Cabezas/Reuters)

Birds fly over the Atomic Bomb Dome in Hiroshima, western Japan July 29, 2015. On August 6, 1945, the U.S. dropped the atomic bomb on Hiroshima, killing about 140,000 by the end of the year in a city of 350,000 residents, in the world's first nuclear attack. Three days later, a second atomic bomb was dropped on Nagasaki. Influenced by the shadows scorched into outdoor surfaces by the heat of the blasts 70 years ago, Reuters photographer Issei Kato pays homage to survivors, residents and historic buildings in both cities in a personal project that captures the shadows of today. (Photo by Issei Kato/Reuters)